## MAR I 

## 2 STATE OF IDAHO DEPARTMEI'..JT OF ENVIRONMENTAL QUALITY 

### GfFICE

# m:tHE

### EXECUlIYE

1410 North Hilton· Boise, Idaho 83706 • (208) 373-0502 C.L. "Butch" Otter, Governor Toni Hardesty, Director



### March 9, 2009

Michelle Pirzadeh, Acting Regional Administrator USEPA, Region 10 1200 Sixth Avenue, Suite 900 Seattle, WA 98101 DearMs. Pirzadeh: Onbehalfofthe Governor ofthe State ofIdaho and as the director ofthe Idaho Department ofEnvirorunental Quality (DEQ), I am submittingto you Idaho's recommendations for area designations for the 2008 revised eight-hour ozoneNational Ambient Air Quality Standard (NAAQS). Section 107(d)(1) ofthe Clean AirAct defines an area as nonattairunent ifit is violating the NAAQS orcontributing to a violation in a nearby area. Core Based Statistical Area (CBSA) or Combined Statistical Areas (which includes two or more CBSA's) associated with violating monitor(s) serve as the startingpoint or "presumptive"boundary for the geographic extentofa nonattairunent area. Forrural areas the presumption is thatthe designation will be made for the entire county in which the monitor is located. Three complete calendar years ofFederal Reference Method (FRM) ozone datahave been evaluatedfor three monitors in the state ofIdaho (Table 1). Per CFR requirements, DEQ operates two monitors in the Treasure Valley (Boise City-Nampametropolitan statistical area (MSA)) and one monitor in the Coeur d'Alene MSA in north Idaho, Idaho's ozone monitoring network is designed to assess population exposure to the highest expected ambient concentrations in populated areas. Data collected from these monitors indicate attairunent ofthe eight-hourozoneNAAQS; therefore, Idaho is recommending attairunentlunclassifiable designations for these areas:• Boise City-Nampa MSA, including: -Ada County -Boise County -Canyon County -Gem County -Owyhee County

• Coeurd'Alene, ID Metropolitan Statistical Area: -Kootenai County The rest ofthe state should be designated as attainmentlunclassifiablefor the eight-hour ozone NAAQS since no monitoring is taking place. 2008 monitoring datahas not been certified and is notfinal. DEQ is working with Region 10 to address certain "missingdays" for its WhitneyElementary School monitor in Boise. DEQ is confident that this monitor will meet all Appendix P datacompleteness requirements once the demonstration is made to Region 10 and concurrence is accepted. The missing days will then be appropriately coded in AQS, and DEQ will complete the data certification process. A similar situation exists for the Lancaster monitor in north Idaho. In both cases, the three-year aggregate data completeness falls one percentage point shortofthe required ninety percent. All data must be certified by July 1,2009. In the future, should it be necessary to redesignate an area as "nonattainment," we intend to evaluate the appropriate EPA guidance and any other relevant considerations to determine presumptive boundaries for that area, rather than default to CBSA or county boundaries. IfEPA has any further questions orconcerns, please coordinate through Martin Bauer, DEQ, Air Quality Division Administrator (208/ 373-0552). Sincerely, ",'

# ((O~~ Toni Hardesty Director

c: Governor Butch Otter Bonnie Butler, Office ofthe Governor Martin Bauer,DEQ Bruce Louks, DEQ

### Table 1. 

### 2006- 2008 Ozone Monitoring Summary, Idaho Department ofEnvironmental Quality Year Site Airs ID 1st max 8-hour

ave ppm 2nd max 8-hour

ave ppm 3rd max 8-hour ave ppm 4th max 8-hour ave ppm Data Completeness % 2008 Lancaster Rd
- Hayden 160550003 0.061 0.06 0.059 0.059 93 2007 Lancaster Rd
- Hayden 160550003 0.072 0.071 0.071 0.067 95 2006 Lancaster Rd
- Hayden 160550003 0.075 0.068 0.068 0.068 78 3-yr design value 0.064 3-yr average data completeness 89 2008 ITO - Boise 160010019 0.079 0.075 0.072 0.072 80 2007 ITO
- Boise 160010019 0.082 0.081 0.080 0.080 58 2006 ITO
- Boise 160010019 0.078 0.076 0.074 0.074 84 3-yr design value 0.075 3-yr average data completeness 74 2008 Whitney
- Boise 160010030 0.077 0.074 0.072 0.069 92 2007 Whitney
- Boise 160010030 0.086 0.085 0.078 0.076 84 2006 Whitney
- Boise 160010030 0.09 0.088 0.083 0.082 88 3-yr design value 0.075 3-yr average data completeness 

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